Universal damper for the torsional vibrations of coaxially revolving shafts



Feb; 20, 1945. R. MATTEUCCI UNIVERSAL DAMPER FOR THE TORSIONAL VIBRATIONS -OF COAXIALLY REVOLVING SHAFTS 2 Sheets-Sheet l Filed NOV. 16, 1939 Feb. 20, 1945. R. MATTEUCCI 2,369,679

UNIVERSAL DAMPER FOR THE TORSIONAL VIBRATIONS OF COAXIALLY REVOLVING SHAFTS Filed Nov. l6, 1959 2 Sheets-Sheet 2 Eff/2 6"- 5 522'04:

Patented Feb. 2t), 1945 "UNIVERSAL!- DAMPER FOR' TH-EETORSIONAL V-IBRATIONS GF COAXIALDYEBEVOLVINGv 2.3SHAETS tflaifa' lr Matteu cifl l l .v st iLin-tj tl J Al r ii'lflzop r y G todian tzAp plication November 16, '1939, SerialiNb. 30 83.5

wrln'sltalyrlfiovember Hit-.1938

zlgclaims. (01:174-514.)

Dampers-f the torsionalvi-brations of rotating sh'afts. are known in which the passive work for: the .l-damping effect, ld'one at the expense. of

the energy -:transmitted "by 2 them, is "effected in dependenee on -ang ii-lar displacements of masses,

with regard to the shaft, set up by their inertia I reactions'to' the'distiirbances of the rotary motio'n set I up by' 'the Said; torsional-vibrations. It is also a known-practice to fit to the resilient joints 1 of "revolving V shafts, dampers of the --oscillatory deformations or the resilient parts producin'g' passive iworkat th'e expenseofthe said deformations. 1

- Neither -o'f these' types of damper is able-to damp out 'all the torsional vibrations of shafts.

Thef-former damp out only those vibrations which present tad-them the loop -zone inwvhiehg'as it is known, the rotary motion of "the shaft is dis- Barbed:angularlw-while'they are-not responsive to those-vibrationswhich present to-them'the node where the-rotary motion is-not disturbed.- The-"latter behave. inexactly the opposite-manner, 'being quite insensibleto' those-vibrations which occur: to them inthe loop; as'they do not modify' the-icoup1e acting-"on the resilient: joint;

inertia,= -there' are r collected: hmtheukinetic; ener y their;loop components. rl'The selectov as arranged in (combination v-withxidamping members wwhiich transformithe collected energy into; passivevwwk through) the oscillatory-'ideformaztionsI ofnatheoresilient member, amid: ithrou'ghi the iosdillatoryadisplacementsof-ztheinertia masses; T x v :Thanks to' thei' selector formed by fiht-LEIYBSlliBht deformable: memb'errsandi the imassess'movingeby transmitted aiongzthe centrerzlinezbyziallfi the? torsional vibrationstwithout; di stinotiongstwo distinct and centinuous ceurrentsnof ienergy nwhich zeare progressively: transtormed intoji'passive workcby the two :trlan's'former idamperi-zmembers, so that all the vibrations, without 'exceptioneare'damped byl the dissipation :ofiithe: kinetic 2 .ene-r-gys. setlsup in'fithem by the-excitinglimpulsesisorzby; opposing inother manner-te the-resonanee; a

' :The'adamping transformerimembers whichiproduce the damping sefiortwrewpreferably thlocks t arranged in la;tci rclei'coaxiallyuaroundithe shaft.

but "comeintowaetion "if, at the -point'at whieh the are amounted, therehappens to be a node or;-a= prevalently nodal zone of vibrations; 1 as a in suehl zones the torsional vibrations 'developin theishaft torsional stresses. I v

An object of':-Jthe present invention is to provide-awdamper capable of acting universally on all =torsiona1 vibrations whether .in a node or nodal zone; or in' a loop or loop-zone. Another object oft-he invention -is-to automatically vary the intensity of the damping effort indirect ratio to the variations in the-speed of rotation. Another object is to be able-to regulate the --sensi-tiveness of the damper; and a further object-is to I be able to regulate this" 's'ensitiveness independently for the vibrations whioh act upon the damperin the loop-Y zones andg-for those which act on itin the nodal-zones. r I

- This damper;- which forms a group intended -to inserted 'betweentwo coaxially-rotating shafta one driving and the other driven; is charaeterized by-a'selector consisting of laresi-lient deformable member mounted on the centre The of the shafts -in--such ar manner as to be deformed in an oscillatory sense by' the vibrations acting upon it -with a-r node or withtheir nodal compon'ents;- and by :inertia masses angularly 'moveable around the shaftand' ar-ranged in'gsu'ch a way asfto'-'b movedein anoseillatory sensejby those Vibrations which *actnpon it-bya loop or with These: ablocks-Lmider s thexinfluenceeof centrifugal force. oreazcomhinationrof this :and theszaction of isprings..orzotherlzknowm suitabl uneansa; press against the inne'rzisurfaee' ofrttn ianmilant'member which surrounds 1 them anduproducetthieir effect by sliding 1' backwards eand 2 fonwards, ziunder the I influence szthe resilient: de'formab orofithe inertia masses. s i

rhythmic I impulses I of theee some :forms of re'aliza'tiom ofzthe object: ofsiahe invention are v'sh'owni-imerely .by'riway rof :examp1e;iin' the annexedixdrawingszini'iwhieh:iFig.this longittidinalzseotioni ofi onevform of. theiuniversal dam-peri Figszrziaandnasairei partial eross sections on nes32= --;:.2a:.-;and-; 3;r.-ee3:c.1-iofoEig.1-1; f-Eig; Ari .isaa longitudinal;seetionalwiewmfl another :for-m-tsof :universal .wiibr'ationidamper, 'rEig. :.is a a sectional view ofaainnodtfieation taken-onithefline V-, 5V1Of Fig.6. f t t v '1' Fig. 1:6 is azssection'al 1 view tweenon-- the line VI- VI' of Fig'sfi.

.i-Eig; This amend-mew of a modi fid driv-i-ngconnection betweenthe dru-m5andthe iher tia inasses.

ample, in' Eig. 1 i the damper is applied on; the line shafting'g'ef a turbine di iven fshipr The-prop'ellor shaft t is driven by the shaft-2 of'ali'oidi- 'nary reducing gear"'giriven b this-application," the dri hgtorque, I I stant; and"-the"-resistant 0 load collpl'e heing' also substantially'constantaiigl'ioiilyf tigijbd byjfithe wan -vib afibn ii resets mite-renath e'rerbr the elastic dformable" member whieh serves to select and collect by its deformations the kinetic energy of the vibrations acting with a nodal character, has but a slight elastic work to perform. It is therefore constituted only by a bar 3, stressed by the driving torque to a high specific torsion load and which therefore effects fairly ample torsional deflections in consequence of the disturbances of the rotary moment set up in it by the torsional vibrations of nodal character. This bar 3 is arranged inside the shaft 2 of the reducing gear, which is hollow, and 'coaxially therewith. The right hand end of the bar 3 engages the shaft 2 by means of grooves and its left hand end engage in a similar manner with a hub of a drum 4 fixed to the end of the propeller shaft I. At the left hand end of the reducing gear shaft 2, opposite the bottom of the drum 4, is fixed a disc 5 which is provided with a number of teeth 5 regularly spaced and projecting from its left face. The teeth 5', through an equal number of slots 4' in the drum, penetrate for a certain distance into an annular recess 4 arranged in the periphery of the drum 4, which recess is preferably divided into two compartments by an intermediate diaphragm 6, loose with regard to the drum. Between the said teeth 5 are engaged angularly with regard to the centre line of the shaft, but free to move radially, an equal number of friction blocks 1 lodged in one of the two compartments of the recess 4. These blocks 1, which form together a crown, makecontact, with their faces furthest from the axis, with the inner surface of the peripheral recess 4 of the drum against which they are pressed in the manner which will be described later.

The nodal action vibrations disturbing the intensity of the driving torque applied to the elastic member 3, set up in it fluctuations of the deformations of the torsion and consequently cause a corresponding oscillatory displacement of the blocks 1 in the recess 4 of the drum 4. As these blocks are pressed against the inner surface of the recess 4 of the drum by centrifugal force, they produce, in their to and fro sliding on the said surface, the passive damping work on the nodal action vibrations.

Within the said recess 4 of the drum 4 is located, alongside the crown of blocks 1, a loose ring 8 which, reacting by inertia to the disturbances of the rotary motion set up in the drum 4 by the loop action vibrations, moves on it angu-' larly with an oscillating motion. On this ring 8 is fitted a series of blocks 8 retained on the ring 8 in the direction of rotation by movable pins 9 lodged in substantially radial'slots cut partly in blocks 1 can be provided, on their periphery, with a friction shoe 1, similar to the blocks 8 of the inertia ring 8 and similarly retained on the relative block 1 by moveable pins 9 lodged in slots cut in part in the thickness of the block 1 and in part in the friction shoe 1. In this case the pressure exerted by the block on the inner surface of the recess 4 is equal to the sum of the centrifugal actions developed in the block 1, in the friction shoe 1 and in the pins 9'. Also in this case the pressure exerted by the blocks 1 can be integrated by springs Ill lodged in suitable recesses in the block and in the friction shoe.

Thanks to the above described conformation the pressure with which both the blocks 8 of the inertia ring 8, and the block 1 with their friction shoes 1 are pressed against the inner surface of the recess 4, abstraction made of the pressure exerted by the eventual springs Ill and I0, is furnished by centrifugal force and i therefore proportional to the square of the speed of rotation of the whole, so that also the damping effort is proportional, the displacement of the blocks being equal, to the square of the said speed.

and has therefore to assume the constructional forms and dimensions of a real and true flexible coupling of considerable power. In this case, while one part of the elastic deformations is utilized to perform the work of damping the torsional vibrations, another part of it reduces the cyclic irregularities of the driving torque and of the rotary motion dependent upon it, thus attenuating the stresse set up by the torsional vibrations produced by the said irregularities.

In Fig. 4 is represented a coupling of the known type described in British Patents 508,425 and 510,104 which lends itself well to this application. Any other known type of flexible coupling may, however, be employed.

the thickness of the ring 8 and partly in the thickness of the blocks 8, which are thus free to move in a radial direction under the influence of centrifugal force and are pressed against the internal surface of the recess 4 of the .drum 4. When, by reason of loop action torsional vibrations, the inertia ring 8 i subjected to oscillatory angular movements with reference to the drum 4, the blocks 8 rub with a reciprocating motion against the inner surface of the recess 4 and perform the passive work of damping the said vibrations. The pressure exerted by the blocks 8 on the inner surface of 4 by the action of the centrifugal force developed in them and on the moveable pins 9, can be eventually integrated by spring l0 also located in suitable recesses in the ring 8 and in the blocks 8.

The blocks 1 ar pressed against the-inner sur The inertia rings 8 and 8 with their relative blocks for the damping of loop action vibrations, in every way similar to those already described, are mounted respectively on the drums 4 and 5 of the discs 4 and 5 which carry respectively the lugs 4 and 5 engaging with the elastic members 38 of the joint.

The blocks 1 for the damping of nodal action vibrations, revolving together with the disc 4 by means of special engagement pieces 3| fixed to the drum 4, but free to move'radially, act on the drum 5 revolving together with the shaft 2, through the joint action of oscillatory movements determined by the deformations of the elastic.

group caused by the nodal action vibrations, and by the pressure set up in them by any suitable means.

The assembly of the blocks which produce the damping effect forms three coaxial annular groups, located alongside the elastic group.

It is evident that, the lower the speed of the driving shaft, the larger must be the inertia masses of the selector intended to collect the kinetic energy of the vibrations acting on it with a loop or with loop components. In case where the speed of the driving shaft is low it is therefore advantageous, in order to avoid the use of drives one or more adherence rollers 32, of

by a spring 36, so that the two rollers ar held in adherence with the drum 4 at diametrically opposite points. On the spindle 33 of each ofthesaid rollers is mounted a secondary drum 34 conof coaxially rotating shafts comprising, a driven shaft and a driving shaft, an elongated resilient member connecting said shafts, a drum rotated by said shafts having circumferentially spaced slot therein, a disc rotated by said shafts and arranged adjacent said drum, circumferentially spaced teeth carried by said disc projecting into the slots of said drum, a plurality of circumferentially movable and radially movable friction blocks arranged within the drum and moved by said teeth, a ring arranged within said drum,

and other blocks carried by the ring and adapted to move in radial directions under the influence of centrifugal force and to engage said drum.

2. A universal damper of torsional vibrations of co-axial rotating shafts comprising, adriving shaft and a driven shaft, means including a resilient member connecting said shafts for driving the driven member from the driving" member, drum means surrounding the axis of the shafts, a disc rotatable with said shafts and arranged adjacent to said drum means, a plurality of circumferentially movable and radially movable friction blocks arranged within the drum means and operatively connected with saiddisc, a ring arranged within said drum means, and other blocks carried by the ring and adapted to move in radial direction under the influence of centrifugal force and to engage said drum means.

RAFFAELE MA'I'I'EUCCI. 

